ST. LOUIS –– A Missouri federal court overseeing a talc powder ovarian cancer case has struck causation testimony from a plaintiff expert, ruling that he was not properly disclosed as an expert witness testifying on causation.

In the Feb. 9 ruling, the U.S. District Court for the Western District of Missouri ruled that the expert’s testimony was “clearly expert opinion that was developed outside” his treatment of the patient and that allowing such testimony would prejudice the defendants.

Michael Blaes filed the lawsuit, contending that his wife’s ovarian cancer was caused by her use of Johnson & Johnson’s Baby Powder ...